Computer Bus

Computer Bus is an electrical pathway through which the processor communicates with the internal and external devices attached to the computer.  Bus transfers the data between the computer subsystems and between the computers and sends the instructions and commands to and from the processor the different devices. It connects all internal computer components to the main memory and the central processing unit (CPU).

It can logically connect many peripheral devices that can easily communicate with the CPU. A bus is also known as the data bus, address bus or the local bus.   The size of the computer bus is important because it determines that how much data can be transferred at a time.  Additionally it has the clock speed, which is measured in the MHz.  There are different types of the buses which are discussed below.  The name of the bus is determined by the type of the signals it carry and the operations it performs.

Data Bus

It carries the data between the different components of the computer.

Address Bus

It selects the route that has to be followed by the data bus to transfer the data.

Control Bus

It decides that whether the data should be written or read from the data bus.

Expansion Bus

It is used to connect the computer’s peripheral devices such as printer, modem and scanner with the processor.

Similarly several different types of the buses are being used on the Apple Macintosh computer.  In the newer Apple Macintosh systems, the Nubus has been replaced by the PCI.

Buses can be parallel and serial.  Today, most of the computers have internal and external buses to connect the internal and external devices to the main memory and CPU.  Depending on the type of the bus and computer the bus’s operation can be unidirectional or bidirectional.